This invention relates to cellular communications and, in particular, to a signal translating repeater that enables a terrestrial (ground-based) mobile subscriber station to provide wireless telecommunication services in both the terrestrial (ground-based) and non-terrestrial regions.
It is a problem in the field of cellular mobile telecommunication services to provide customers with high quality communication services in a unified manner via a wireless communication medium. Existing cellular mobile telecommunication systems serve terrestrial (termed ground-based herein) mobile subscriber stations, but this service was traditionally not extensible to non-terrestrial mobile subscriber stations due to signal interference problems between ground-based and non-terrestrial mobile subscriber stations. The above-noted U.S. Patents disclose a non-terrestrial mobile telecommunication system and a mobile subscriber station operable in such a system, which provides subscribers with cellular mobile telecommunication services in the non-terrestrial region. However, the mobile subscriber stations used in the ground-based cellular mobile telecommunication system and the mobile subscriber stations used in the non-terrestrial cellular mobile telecommunication system are traditionally architected to operate in only their associated cellular mobile telecommunication system.
Thus, the existing mobile subscriber stations are incapable of being used both in ground-based cellular mobile telecommunication systems and non-terrestrial cellular mobile telecommunication systems. Therefore, subscribers must presently use one mobile subscriber station for the ground-based cellular mobile telecommunication system and another mobile subscriber station for the non-terrestrial cellular mobile telecommunication system. Each of these mobile subscriber stations has an assigned telephone number and the communication services provided to the subscriber are therefore disjunction.
The mobile subscriber station described in the above-noted U.S. patent application Ser. No.: 09/379,825, titled Ubiquitous Subscriber Station, provides wireless telecommunication services in both the terrestrial (ground-based) and non-terrestrial regions. This unique mobile subscriber station enables the subscriber to receive wireless cellular mobile telecommunication services in a unified manner in both the terrestrial (ground-based) and non-terrestrial regions.
However, for subscribers equipped with a traditional ground-based mobile subscriber station, there is no provision for receiving cellular communication services in an aircraft.
The above described problems are solved and a technical advance achieved in the field by the signal translating repeater, located in the aircraft, that enables a traditional ground-based mobile subscriber station to provide wireless telecommunication services to a subscriber in both the terrestrial (ground-based) and non-terrestrial regions. The signal translating repeater achieves this by extending the usage of existing ground-based cellular communications to non-terrestrial cellular communications in a manner that avoids the possibility of signal interference between the ground-based mobile subscriber stations and ground-based mobile subscriber stations located in a non-terrestrial location.
In particular, the signal translating repeater is located in the aircraft and receives frequency translated cell site cellular signals, comprising cellular radio frequency communication signals from a cell site that are in a mode compatible with ground-based cellular communications but shifted in frequency from the standard ground-based cellular radio frequency communication signals to other radio frequencies that are allocated for non-terrestrial cellular communications.
The signal translating repeater automatically translates the received frequency translated cell site cellular signals from the radio frequencies that are allocated for non-terrestrial cellular communications into the ground-based cellular signals, comprising radio frequency communication signals that are in a mode compatible with ground-based cellular communications, used by the ground-based mobile subscriber stations located in the aircraft. The subscriber therefore can use their ground-based mobile subscriber station in all locations for uninterrupted wireless communications services, either using one telephone number for all locations, or by having a telephone number that is assigned for ground-based wireless communications services and another telephone number that is assigned for non-terrestrial wireless communications services to assist in the direction of the call completion.
The existing ground-based cell site transmitter/receiver antenna installations can be used to serve non-terrestrial mobile subscriber stations by the addition of non-terrestrial antenna elements and the operation of the non-terrestrial transmitters and receivers at radio frequencies that are not used for ground-based cellular communications. In this manner, non-terrestrial cells can be created in the region of space adjacent to and overlying the existing ground-based cells without the possibility of interaction between the existing ground-based cellular mobile telecommunication system and the non-terrestrial mobile subscriber stations. To the mobile telecommunication switching office, the non-terrestrial cells all operate in harmony with the existing ground-based cell sites with no discernible differentiation among cells or stations, whether ground-based or non-terrestrial in nature. A further optional solution to the interference problem is the manipulation of the control channels in the frequency translated cell site cellular signals such that the cellular signals transmitted between the signal translating repeater in the aircraft and the cell site cannot cause either a ground-based cell site receiver or ground-based mobile subscriber station receiver to receive and interpret these control signals. The designation of a set of control channels within the plurality of available voice channels in the cellular channel space represents the method of bifurcating the volume of space into two disjunct regions: ground-based and non-terrestrial.